Cleaning process and compositions for post-emulsifier inspection penetrants



3,422,670 EMULSIFIER Jan. 21, 1969 CLEANING PROCESS AND COMPOSITIONS FORPOST wwkukwtzmo Eamon; 0 I I INVENTOR. I y 62 Z United States Patent3,422,670 CLEANING PROCESS AND COMPOSITIONS Filed June 16, 1965, Ser.No. 464,360 US. Cl. 73-104 Int. Cl. G01n 19/00 14 Claims ABSTRACT OF THEDISCLOSURE A cleaning method and applicable cleaning compositions forremoving surface penetrant in inspection processes in which alow-activity wash liquid is applied to the surface to be cleaned, usingagitation, the wash liquid being prepared by diluting anemulsifier-coupler with a suitable solvent-rinse liquid to a point wherethe solubilizing action of the mixture is at a low value sufficient toprovide a minimum degree of stripping of defect entrapments ofpenetrant. The low activity of the diluted emulsifier-coupler preventsexcessive solubilization of the penetrant, yet permits removal ofpenetrant with the assistance of mechanical agitation.

This invention relates to a process of and materials for cleaning orremoving inspection penetrant materials from parts in post-emulsifierpenetrant inspection processes. More particularly, the invention relatesto a penetrant removal method which is intended to yield a high level offiaw entrapment efiiciency in the detection of surface discontinuitiesby the post-emulsifier penetrant inspection method.

In general, the post-emulsifier penetrant inspection process employs apenetrant liquid containing a fluorescent or visible color tracer dye,said liquid being normally insoluble or non-washable in a wash medium asemployed in the process. Parts to be inspected for surfacediscontinuities are immersed in the penetrant, whereupon the dyedpenetrant enters any surface discontinuities or flaws which may bepresent and forms entrapments therein. Excess penetrant is allowed todrain from the parts, or is wiped off or blown off by an air blast.Thereupon, an emulsifier-coupler liquid is applied to the parts, saidemulsifier-coupler having the ability to render the normally insolublepenetrant soluble in the wash medium.

Following a suitable emulsifier dwell time, during which theemulsifier-coupler blends with the film of penetrant remaining on thesurface of a part being treated, the part is washed in a wash medium,thus flushing off the soluble or emulsified surface mixture and leavingany nonemulsified penetrant entrapments. These penetrant entrapments arethen detected, usually by a visual inspection for their fluorescence orcolor.

The so-called post-emulsifier penetrant inspection process may take avariety of forms in that different kinds of penetrants, emulsifiers, andwash media may be employed. However, all post-emulsifier penetrantinspection processes have one feature in common, that being the use ofan emulsifier or emulsifier-coupler which acts to render the normallyinsoluble penetrant washable in the wash medium.

The most commonly employed post-emulsifier inspection process is theso-called oil-phase P/ E process. In this process, the penetrant liquidis a water insoluble oil, the emulsifier is an oil-water coupler whichhas the ability to simultaneously dissolve the penetrant oil in itselfand form a washable mixture in water, and the wash medium is water.

Another type of post-emulsifier penetrant process is "ice the so-calledinverted system, which is described and claimed in my copendingapplication, Ser. No. 452,861, filed May 3, 1965. In this invertedprocess, the penetrant is an oil-insoluble glycol liquid, theemulsifier-coupler is a glycol-oil coupler such as a glycol-ether or analcohol, and the wash medium is a mineral thinner.

Regardless of the type of post-emulsifier penetrant inspection processwhich is employed, a cleaning step is always employed for removingsurface penetrant on parts being processed, leaving only penetrantentrapments in surface flaws. This may be accomplished by the so-calledsolvent remover method, where a strong solvent is employed which flushesthe surface clean. This method suffers from the drawback that it tendsto strip penetrant out of shallow entrapments. The post-emulsifiermethod, using a penetrant-wash coupler, is much better and may be madeto yield a controlled high level of flaw detec tion performance.

The flaw detection performances of post-emulsifier penetrant inspectionsystems depend chiefly on the emulsifier strength or activity and therate at which the emusifier diffuses into flaw entrapments to renderwashable the penetrant contained therein. Even though post-emulsifierpenetrant inspection processes have been developed to a high level ofperformance efiiciency, there are cases where these processes fail tomeet the requirement of high sensitivity in the detection ofmicro-surface-fiaws. For example, where large parts are being inspected,it may take a relatively long time to apply an emulsifier and then washoff the surface mixture. In such cases, an excessive entrapmentstripping action may occur, even with an emulsifier which is designed toa high level of flaw entrapment efficiency. Also, by virtue of the factthat a practical emulsifier formulation must have a reasonable penetrantcontamination tolerance, the flaw entrapment efficiency must always besomewhat less than as described hereinafter. Hence, presently availablepenetrant cleaning or removing processes leave much to be desired intheir ability to perform a cleaning function without at the same timecausing an unwanted stripping out of the flaw entrapments.

It has been found that it is possible to provide a satisfactory surfacecleaning function in a post-emulsifier type of a penetrant processwithout an unwanted removal of small penetrant entrapments.

The principal object of the invention, therefore, is to provide animproved method for cleaning normally insoluble and non-washableinspection penetrants from surfaces.

Another object of the invention is to provide an improved penetrantcleaning method which yields a high level of flaw entrapment efficiency.

Still another object of the invention is to provide a penetrant cleaningmethod which is economical to use.

A further object of the invention is to provide a penetrant cleaningprocess which provides a surface cleaning and scrubbing action withoutany deformation or damage to the surface being cleaned.

A still further object of the invention is to provide penetrant cleaningand emulsifying materials which yield high levels of flaw entrapmentefficiency.

A better understanding of this invention may be had from the followingdetailed description when read in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a diagrammatic representation in cross-section of the actionof a conventional emulsifier cleaner in removing a surface penetrant inthe region of a flaw entrapment;

FIG. 2 is a diagrammatic representation of the action of a cleanermaterial applied in accordance with this invention; and

FIG. 3 is a chart of emulsifier-cleaner activity plotted in terms of twoparameters, penetrant contamination tolerance and viscosity.

In order to properly understand this invention and the embodimentthereof, it is first necessary to understand the mechanism of emulsifieraction in removing surface penetrant by the conventional post-emulsifierprocess. Referring, now, to FIG. 1, a small surface flaw 1 is present inthe surface 2 of a part being inspected for the presence of surfaceflaws. Following the application of a penetrant which contains a tracerdye, the penetrant enters the flaw 1 and forms an entrapment 3. Thepenetrant also leaves a film 4 of penetrant on the surface 2.

In the normal post-emulsifier procedure, an emulsifier is applied on thesurface, either by spray or dipping, leaving a layer 5 of the emulsifierover the entire surface. This emulsifier layer 5 blends with thepenetrant layer 4, forming a wash-removable mixture. However, theemulsifier layer 5 also diffuses down into the surface flaw 1 to acertain depth indicated by line 6. The depth of this diffusion by theemulsifier into the flaw entrapment depends on the emulsifier dwell timeand its viscosity, and it is found that for presently employedemulsifiers, the diffusion will progress substantially to the bottom ofvery small surface flaws within a few seconds following application ofthe emulsifier. Even if the emulsifier does not diffuse completely intothe penetrant entrapment, thereby rendering it completely washable, andassuming that it diffuses only part way to a point as indicated by line6, then there will still be a substantial portion of the diffusion zonewhich will be rendered wash-removable. This portion is indicated as theemulsifier-penetrant mixture which lies outside of the washability breakcondition which occurs at line 7. The exact location of line 7 dependson the strength or activity of the emulsifier, and may be determined bymeasuring the penetrant contamination tolerance of the emulsifier asdescribed in detail in my above-mentioned copending application, Ser.No. 492,676, now U.S. Patent No. 3,311,479, for Penetrant InspectionProcess and compositions.

The flaw entrapment efliciency, or the percentile proportion of theentrapment which remains non-washable, is always somewhat less than 100%and is usually on the order of 70% or less for practical emulsifiermaterials. Up to the present time, there has been no practical way toremove the unwanted surface penetrant from parts without also strippingout a portion of the desired flaw entrapment.

It has been discovered that certain liquid materials which exhibitlittle or no solubilizing action on a penetrant material may be made toprovide an efficient cleaning action on surface penetrant withoutremoving any of the desired entrapped penetrant in surface flaws. Suchtrant material may be made to provide an efficient cleanwhich have beendiluted or extended by the wash medium to a point where their couplingaction has been reduced to an apparently negligible value. Furthermore,If such materials are applied to a surface with sufficient surfaceagitation, an effective cleaning action will take place. A suitablesurface agitation may be obtained by a spray application of the cleaningmaterial. Ultrasonic agitation of the surface could be employed, butthis is not usually desirable for the reason that the ultrasonic energydoes not confine itself entirely to the surface of the part and may tendto drive out some of the entrapment of penetrant from flaws.

Referring, now, to FIG. 2, a spray nozzle 10 delivers a stream of liquidspray 11 toward the surface 12 which contains a flaw 13. On the surface12, there is a film of normally non-washable penetrant 14, and anentrapment of penerant 15 is in the flaw 13. As the liquid spray 11strikes the surface film of penerant 14, it acts to scrub the surfaceclean. Individual droplets of the spray 16 are usually large withrespect to the flaw 13, and they do not enter the flaw opening. Thus,the cleaning action of the spray is confined to the surface of the part,and

the desired penetrant entrapment remains substantially intact throughoutthe surface cleaning operation. Due to the liquid character of thespray-scrubbing mixture, there can be no deformation or damage to thesurface being tested.

The essence of this invention lies in the surface scrubbing action whichis obtained from a spray or stream of a liquid which has a small butfinite solvent action on the surface penetrant. It will be seen at oncethat if the solvent or coupling action of the liquid spray is made toogreat, then there will be no particular gain in the flaw entrapmentefficiency over the conventional postemulsifier and wash action asdescribed above. On the other hand, if the solvent-coupling oremulsifier-coupling action of the cleaning liquid is made too small,then the cleaning action will progress at an excessively slow rate.

If a spray of plain water is applied on a surface film of an oil-phasepost-emulsifiable penetrant, no cleaning action whatsoever will takeplace. However, the addition of a small amount of an oil-water couplingagent in the spray will permit the scrubbing action to take place, andthe surface will be scrubbed clean.

Many materials may be employed as cleaning agents for use with themethod of this invention. For example, if an oily water-insolublepenetrant is to be cleaned from a surface by the spray-scrubbing methodof this invention, the coupler-cleaner may be a water-diluted solubleoil, or it may be a water-diluted penetrant inspection emulsifier of thetype described and claimed in my copending application, Ser. No.497,058, now U.S. Patent No. 3,349,041, for Gel-forming InspectionPenetrant and Emulsifier Compositions and Processes. Any one of a widevariety of surfactant materials may be employed in diluted andrelatively inactive form for the sprayscrubbing cleaning method. Also,any one of a wide variety of liquid solvents such as alcohols, glycoleithers, dimethyl formamide, N-met hyl pyrrolidone, or other materialswhich have a degree of mutual solubility for both oil and water may beutilized in a more or less diluted form with water such that the coupleraction is relatively small.

In the case of glycol-type penetrants, glycol-ethers, various alcohols,and a wide range of surfactant materials, and even soluble oils, may beused in diluted or extended mixtures in a mineral thinner, therebyproviding a sprayscrubbing cleaning action on surface penetrants withoutan excessive removal of penetrant entrapments.

It has been found that any material which has a mutual solubility orcompatibility with the penetrant and the wash medium may serve as aspray-scrubbing cleaner. The degree of flaw entrapment efiiciency whichmay be achieved depends on the penetrant contamination tolerance of thespray-scrubber mixture. In conventional emulsifier materials, aconvenient method for measuring the penetrant contamination tolerance isto test the washability of sample smears of penetrant-emulsifiermixtures on a clean anodized aluminum panel, and thereby determine thepercentage of added penetrant above which the washability of the mixtureis destroyed.

Conventional emulsifier-couplers exhibit penetrant contaminationtolerance values which may range from a few percent to 100% or more ofadded penetrant. In such materials, the percentile flaw entrapmentefiiciency may be expressed as 100 T where T is the penetrantcontamination tolerance expressed in terms of percent added penetrant.Thus, in an emulsifier-penetrant combination where the emulsifier willtolerate 15% added penetrant up to the washability break, the fiawentrapment efiiciency is 100 -15 or Even this relatively high efiiciencyfactor does not necessarily lead to a good retention of flaw entrapmentsduring the surface cleaning operation, for the reason that a prolongedcontact of the emulsifier with a flaw entrapment may render the entireentrapment washable so that it is stripped out in the wash operation.

An empirical relationship which has been found for the behaviour ofemulsifier-cleaner materials with respect to cleaning activity isillustrated in FIG. 3. Referring, now, to FIG. 3, the two Significantperformance parameters of emulsifier-cleaners, namely, penetrantcontamination tolerance and viscosity, are plotted on the axes ofabcissas and ordinates, respectively. In this chart, the operating pointof a given emulsifier-cleaner may be entered according to its parametervalues, providing an Activity Quotient value with respect to thediagonal scale of the chart, this Activity Quotient value being theratio of applicable values for penetrant contamination tolerance andviscosity.

A typical emulsifier-cleaner material which is employed extensively inpenetrant inspection processes is the socalled E153 material, which isdisclosed in my abovementioned US. Patent No. 3,311,479 which has apenetrant contamination tolerance rating of 25, meaning that it willtolerate 25% of added dioctyl phthalate reference oil up to the pointwhere its washability is destroyed. This emulsifier also has a viscosityat 100 F. of about 50 centistokes. The activity quotient value for thisproduct would be entered in the chart of FIG. 3 at point 20, where it isseen that the activity quotient value is .5.

Another typical emulsifier-cleaner material, similar to theabove-mentioned E-153 emulsifier, which is used extensively in industryis the so-called E-157 product which has a penetrant contaminationtolerance of 16% and a viscosity at 100 F. of 3.2 centistokes. Theactivity quotient value for this product would be entered in the chartat point 21, where it is seen that the activity quotient value is 5.0.

Another useful empirical relationship with respect to emulsifier actionby normal contact diffusion has been found to be that twoemulsifier-cleaners having different activity quotient values may bemade to yield similar penetrant removal actions by adjusting theirrelative dwell times. It has been found that over a useful range ofoperating conditions, the relative dwell times for equivalentperformance differ by a factor equal to the inverse square root ratio ofthe activity quotient values of the two materials. Line 22 in FIG. 3,and all lines parallel to it, represent locus lines of equivalentperformance, such that points on a given locus line are related to oneanother in such a way that applicable ratios of equivalent performancedwell times are equal to the inverse square root ratios of applicableactivity quotient values.

As an example, in comparing the performance behavior of the E153 productwith that of the E157 material, a locus line 23 may be drawn on thechart such that point 24 represents a dwell time of two minutes asutilized for the E-153 emulsifier. 'This locus line intersects theactivity quotient level of 5.0 for the E-157 material at point 25, whichcorresponds to a dwell time of .63 minute, or about 38 seconds.Comparison tests of the relative penetrant removal action of these twoemulsifier products confirms that they do indeed yield equivalentresults with dwell times of two minutes and 38 seconds, respectively.

Now, referring once again to the objects of this invention, it isdesirable that the so-called spray-scrubber cleaners of the inventionshall have extremely low activity quotient values such that a prolongeddwell time in contact with a penetrant entrapment will produce anegligible degree of solubilization of the entrapment. In practicalterms, it is desirable that the spray-scrubber liquid, as employed inthis invention, shall have a low level of activity such that a dwelltime of about ten minutes in contact with a penetrant film will produceno more, and preferably less, solubilization action than will about oneminute dwell time with a conventional contact emulsifier such as theE-153 material. In other words, the equivalent dwell time of aspray-scrubber must be greater than that of a conventional emulsifier byat least one order of magnitude.

It will be seen from an examination of the chart of FIG. 3 that in orderto accomplish this result, it is necessary to have a very low activityquotient value for the spray-scrubber liquid. For example, if anequivalent performance locus line 26 is drawn on the chart, intersectingthe activity quotient level of .5 for the E-153 product at point 27,corresponding to a dwell time factor of .05, then in order to achieve acondition where a sprayscrubber will yield similar performancecharacteristics with dwell times which are greater by one order ofmagnitude or more, an operating point for the spray-scrubber must besomewhere in the region of an activity quotient level of .005 or less,as indicated by the point 28. Hence, the activity quotient value for apractical spray-scrubber should be on the order of .005 or less. Auseful range of equivalent values for spray-scrubbers has been found tobe from about .00005 to about .05, but under certain special conditionsof operation, where suitable adjustment may be made in dwell time orother factors, the sprayscrubbers may have activity quotient valuesranging from about .0000005 to about .5.

Even though the activity quotient values of practical spray-scrubbersare quite low, the materials will remove surface penetrant to a verysatisfactory degree of cleanliness, while at the same time relativelylittle stripping action takes place on flaw entrapments.

Inasmuch as oil-phase spray-scrubbers are diluted with water so that theresultant viscosity of the spray mixture is close to unity, and inasmuchas inverted system sprayscru bbers are most conveniently diluted with amineral thinner such as kerosene so that the resultant viscosity of thespray mixture is in the range of unity or slightly less, it is seen fromthe chart that a spray-scrubber which is to have an activity quotientvalue of .005 in its diluted form will have an operating point in theregion of point 29, and will exhibit a penetrant contamination toleranceof about .005 This level of penetrant contamination tolerance is toosmall to measure directly, but it is sutficient to permit a satisfactorycleaning removal of penetrant by the spray-scrubbing method of thisinvention.

It has been discovered that any emulsifier-coupler material, regardlessof its chemical structure, may be diluted with its wash medium, and itspenetrant contamination tolerance will drop to a relatively low value.In addition, it has been discovered that even though the penetrantcontamination tolerance is reduced by such dilution to a value muchsmaller than 1%, the mixture will retain an ability to remove surfacepenetrant by a spray-scrubbing technique.

Example 1.To illustrate the phenomenon of sprayscrubber removal ofsurface penetrant, one part of a typical oil-phase emulsifier consistingof a 'mixture of sodium petroleum sulfonate, mineral oil and acombination of hydrophylic and lipophylic surfactants is diluted in tenparts water to form a milky emulsion. 'I he undiluted emulsifier has amutual solubility for water and oily water insoluble penetrants.However, after dilution with water, the emulsified mixture has nodiscernible penetrant contamination tolerance, that factor being reducedto a value of a small fraction of a percent. Spray application of thismixture to a surface film of an oil-phase penetrant will scnub thesurface clean by a slow erosion removal of the penetrant lil m, and willleave penetrant entrapments in flaws to a high level of flaw entrapmentefiiciency.

Example 2.One part of an emulsifier-coupler intended for use as awater-washable penetrant-cleaner for parts which are to be wetted withliquid oxygen, said emulsifier being of the type described and claimedin my abovementioned US. Patent No. 3,349,041, is diluted with 20 partswater to form a milky emulsion. The undiluted emulsifier has in thiscase a mutual solubility for water and oily Water-insoluble penetrants.However, after dilution with water, the apparent solubility for oilypenetrants falls to an apparently non-existent value. Even so, thediluted mixture will act as an effective spray-scrubber cleaner onsurface fil-ms of oily penetrants without removing any of the desiredflaw entrapments of penetrant.

Example 3.Equal parts of ethoxylated nonylpheno-l, having about 9 molsof ethylene oxide per mol of nonylphenol, and diethylene glycolmonobutyl ether are mixed together to form a liquid concentrate. Onepart of this concentrate is diluted with about 50 parts water to form aspray-scrubber solution. Alternatively, the concentrate mixture is fedinto a siphon type water-spray gun in such a way that the water dilutionratio is about 50 to 1. The undiluted concentrate exhibits a mutualsolubility for water and oily penetrant materials; however, the dilutedmixture has apparently no solubilizing action on oily penetrants. Evenso, the diluted mixture provides an effective spray-scrubbing cleanerwhich is low in cost, convenient to use, and yields high levels of flawentrapment efiiciencies.

Example 4.One part of diethylene glycol monobutyl ether is diluted withabout 25 parts of kerosene to form a spray-scrubber mixture for a glycoltype (inverted system) penetrant. Prior to dilution, the diethyleneglycol monobutyl ether exhibits a mutual solubility for glycolpenetrants and for mineral solvent wash media. However, the dilutedmixture has no apparent solubility for glycoltype penetrants. Even so,the diluted mixture provides an effective spray-scrubbing cleaner whichwill remove surface glycol penetrant leaving flaw entrapments ofpenetrant substantially intact. In this example, the diethylene glycolmonobutyl ether may be substituted with any one or a combination of awide variety of glycol-ethers, alcohols and oil soluble surfactants.

The foregoing examples are representative of the many differentpenetrant-wash medium couplers which may be employed as spray-scrubbercleaners. All of the wide variety of suitable materials maybe used inthe same way, yielding an effective spray-scrubber action, the onlyrequirement being that the spray-scrubber mixture shall be prepared bydiluting a. penetrant-wash medium coupler with the wash medium so as toreduce its Activity Quotient value to a satisfactory low level. Theinvention is, therefore, not limited to the materials or formulationsgiven in the examples.

I claim:

1. In an inspection penetrant process involving the steps of penetrantapplication to test surfaces, removal of surface penetrant, andinspection for the presence of penetrant entrapments in surface defects,the step of applying an inspection penetrant to a surface to beinspected for surface discontinuities, and the step of applying a washliquid to said surface, said wash liquid being an emulsifier-couplerdiluted with a solvent rinse liquid, said emulsifier-coupler having amutual solubility for said inspection penetrant and said solvent rinseliquid, and said solvent rinse liquid being nonsolvent for saidinspection penetrant, said dilution being suflicient to provide anactivity quotient of said wash liquid within the approximate range of.0000005 to .5, and said application of said wash liquid being carriedout with vigorous agitation of said wash liquid against said testsurfaces.

2. A process in accordance with claim 1 in which said inspectionpenetrant consists essentially of an oily, waterinsoluble liquidvehicle, said emulsifier-coupler is an oilwater coupler, and saidsolvent rinse liquid is water.

3. A process in accordance with claim 1 in which said penetrantentrapments in surface defects, the step of applying an inspectionpenetrant to a surface to be inspected for surface discontinuities, andthe step of applying a wash liquid to said surface, said wash liquidbeing an emulsifiercoupler diluted with 'a solvent rinse liquid, saidemulsifiercoupler having a mutual solubility for said inspectionpenetrant and said solvent rinse liquid, and said solvent rinse liquidbeing nonsolvent for said inspection penetrant, said dilution beingsufiicient to provide an activity quotient 'of said wash liquid withinthe approximate range of .00005 to .05, and said application of saidwash liquid being carried out with vigorous agitation of said washliquid against said test surfaces.

6. A process in accordance with claim 5 in which said inspectionpenetrant consists essentially of an oily, waterinsoluble liquidvehicle, said emulsifier-coupler is an oilwater coupler, and saidsolvent rinse liquid is water.

7. A process in accordance with claim 5 in which said inspectionpenetrant consists essentially of a glycol liquid vehicle, said saidemulsifier-coupler is a glycol-mineral thinner coupler, and said solventrinse liquid is a mineral thinner.

8. A process in accordance with claim 5 in which said wash liquid isapplied by spraying.

9. A spray-scrubbing cleaner composition for removing inspectionpenetrant in a cleaning step in an inspection penetrant processconsisting essentially of an emulsifiercoupler diluted with a solventrinse liquid, said emulsifiercoupler having a mutual solubility for saidinspection penetrant and said solvent rinse liquid, and said solventrinse liquid being nonsolvent for said inspection penetrant, saidspray-scrubbing cleaner composition having an activity quotient valuewithin the approximate range of .0000005 to .5.

10. A spray-scrubbing cleaner composition in accordance with claim 9consisting essentially of an oil-water coupler diluted with water.

11. A spray-scrubbing cleaner composition in accordance with claim 9consisting essentially of a glycol-mineral coupler diluted with mineralthinner.

12. A spray-scrubbing cleaner composition for removing inspectionpenetrant in a cleaning step in an inspection penetrant processconsisting essentially of an emulsifiercoupler diluted with a solventrinse liquid, said emulsifiercoupler having a mutual solubility for saidinspection penetrant and said solvent rinse liquid, and said solventrinse liquid being nonsolvent for said inspection penetrant, saidspray-scrubbing cleaner composition having an activity quotient valuewithin the approximate range of .00005 to .05.

13. A spray-scrubbing cleaner composition in accordance with claim 9consisting essentially of an oil-water coupler diluted with water.

14. A spray-scrubbing cleaner composition in accordance with claim 9consisting essentially of a glycol-mineral thinner coupler diluted withmineral thinner.

Zyglo and Zyglo-Pentrex: Brochure (73/104) Magnafiux Corporation,copyright 1957 pp. 12 and 13.

JAMES J. GILL, Primary Examiner.

R. S. SALZMAN, Assistant Examiner.

